Delivering water from coal seam gas in Queensland

Sep 2009

Australia

Australia is the driest inhabited continent
on earth, which puts enormous pressure
on providing sufficient water for its
population and agriculture. Queensland
has been one of the worst hit areas and
following several years of drought, many
of its reservoirs are below 20% capacity,
and therefore, new water sources are
extremely welcome.

One new source being exploited is the use
of water from the gas extracted from the
underground coal seams in the state. This
water which in the past was seen as a waste
product, could now provide a valuable
source of additional water. Pipelines are
now being installed to deliver the water to
the local communities and provide cooling
water for the local power stations.

Changes in the weather pattern in Australia have
brought several years of drought to much of the
country. Queensland, in north eastern Australia,
has been one of the worst hit areas, which has
had a major financial and social impact on many
local agricultural communities in the region. The
State has undertaken a number of new initiatives
to reduce water consumption and to reuse water
from existing resources. New desalination plants
have been built but these are expensive and
consume considerable energy, so everyone is
conscious of the value of any additional source
of water.

Australians live on the driest inhabited continent
on Earth and following 10 years of drought, nearly
every Australian city will be forced to find new
water supplies during the next decade, as climate
change and population growth take their toll on
the nation’s already limited water supply. In the
Murray-Darling Basin, which was Australia’s
prime food-growing region, the current drought
is the worst in the country’s recorded history.
Many scientists believe that this signals a
permanent climate shift that is challenging the
country’s capacity to feed itself. Overall, more
than 60 per cent of Australia’s agricultural land
is declared as an exceptional area of drought by
the federal government.

The annual report by the Water Services
Association of Australia said authorities in all of
Australia’s mainland capital cities will need to
find new ways to provide water, such as
desalination and recycling, in the next five to 10
years. The west coast city of Perth has become
the first in Australia to build a large-scale
desalination plant, and other plants have been
built in Queensland and New South Wales. In
Brisbane, the Western Corridor Recycled Water
Project is already supplying water to power
stations in the area and the water will be used
to top up the reservoirs when they fall to a critical
level. The new infrastructure could cost up to
US$ 25 billion during the next decade, and this
will have to be paid for by higher water charges
to consumers.

Water from Queensland’s coal seams

Australia’s east coast is particularly badly affected,
including Queensland in the north east of the
country. However, some towns in the area could
benefit from the utilisation of water from coal
seam gas extraction plants. In the underground
coal seams, the water, gas and coal are fully
integrated, but once water is pumped from a
well drilled into the seam, gas is also released.
Water production is usually greatest in the early
phases of mining, and as water production
reduces, the flow of gas increases.

The gas production companies used to regard
the water as a waste product and allow it to
evaporate in open pools, but in the current
situation, they realise this water could be valuable
in alleviating some of the severe problems from
the drought. The new water source could have
a multiplicity of uses. In its raw form, it could be
used to top up the reservoirs, or after treatment,
it could be used for agricultural irrigation and
human consumption.

New pipelines to revive communities

By 2010, the Queensland Department of Mines
believes that 14,300 million litres of water per
year will be available as a by-product of their
operations. In seven to eight years, it is expected
to be able to supply 100 to 125 million litres of
water per day. Origin Energy, which is the largest
coal seam mining company, estimates that it
could supply more than 5,000 million litres of
water per year, increasing to 25,000 million litres
per year by 2015.

A 25 km 450 mm 12.5 bar water pipe is being
constructed, which will take water to the local
town of Miles as well as supplying cooling water
to the local power station, which was built
specifically to utilise the gas from the coal seams.
The first pipes are now going in the ground –
PE100 pipes produced from BorSafe HE3490-LS
material and manufactured by local pipe producer
PPI in Brisbane.

Although this new water source will not solve all
the water problems in Australia, it will improve
the quality of life for many of the citizens in this
region for many years to come.